Drilling fluid nozzles for drill bits



2 Sheets-Sheet 1 Filed April 21, 1951 6 F M .6 f

IN VEN TORJ' A TTORNfYJ Sept. 27, 1955 E, G. BOICE ET AL 2,719,027

DRILLING FLUID NOZZLES FOR DRILL BITS Filed April 21, 1951 2Sheets-Sheet 2 E/V/U 6. BO/Ce /6 Roberf 6. Pefer w '7 Av Iii d CZMZ gy/Z. v gay/1 5 5 Lia/"1A A T TORNE Y6 United States Patent DRILLINGFLUID NOZZLES FOR DRILL BITS Elvin G. Boice and Robert G. Peter,Houston, Tex., as-

signors to Reed Roller Bit Company, Houston, Tex., a corporation ofTexas Application April 21, 1951, Serial No. 222,212

2 Claims. (31. 2ss 313 This invention relates to new and usefulimprovements in drilling fluid nozzles for drill bits.

As is well known, the usual drill bit is provided with fluid circulatingpassages through which the usual drilling fluid is directed during thedrilling operation. This drilling fluid usually contains abrasivematerial and is circulated in relatively high volume and underrelatively high pressure. The flow of fluid is conducted downwardlythrough the connecting pin at the upper end of the bit and is thendirected outwardly in a manner to eifectively clean the cutter teeth andremove detritus. Because of increased volumes and pressures which havecome into use in recent years, the maintenance of the life of the fluidnozzles has presented a considerable problem.

It is one object of this invention to provide an improved drilling fluidnozzle adapted to be mounted within a drill bit which is constructed towithstand the abrasive laden drilling fluid under high pressure and inhigh volume.

An important object of the invention is to provide an improved nozzleassembly for drill bits which is constructed to eliminate constrictions,cavities and abrupt section changes so as to provide for a streamlinedflow through the nozzle, whereby the drilling fluid is directed into thenozzle outlet with a minimum amount of turbulence.

Another object of the invention is to provide an improved nozzleassembly wherein each nozzle is, in eifect, an elongate passage whichextends from the upper portion of the bit, whereby the division of theflow stream into the various nozzles occurs at a point remote from theoutlet end of each nozzle to thereby prevent undue abrasive wear of thenozzle outlets.

Still another object is to provide an improved method of manufacturing anozzle assembly wherein multiple nozzles may be individually constructedin sections which are adapted to be secured together to form thecomplete assembly, each nozzle having its internal passage arrangedwithout abrupt turns or restrictions to permit substantially streamlinedflow therethrough.

. A still further object is to provide an improved method ofconstructing a nozzle assembly wherein the individual nozzles areassembled and secured together and are thereafter welded in properposition within the bit assembly.

Still another object is to provide an assembly of the characterdescribed wherein the nozzle may or may not have a hardened insert atits outlet end.

The construction designed to carry out the invention will be hereinafterdescribed together with other features thereof.

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawingsforming a part thereof, wherein an example of the invention is shown,and wherein:

Figure l is a vertical sectional view taken through a drill bit andillustrating the improved nozzle assembly mounted therein,

Figure 2 is an isometric view of the nozzle assembly,

Z ,7? l 9 ,@Z 7 Patented Sept. 27, 1955 'ice Figure 3 is an isometricview of the two sections of the nozzle assembly illustrated in Figures 1and 2,

Figure 4 is a side elevation of one of the nozzles,

Figures 5 to 9 are transverse sectional views taken on the lines 55 to9-9, respectively, of Figure 4 to illustrate the cross-sectional shapeof the passage through each nozzle,

Figure 10 is a transverse sectional view taken on the line 1010 ofFigure 2,

Figure 11 is a sectional detail showing a hardened insert within theoutlet end of the nozzle, and

Figure 12 is a transverse sectional view taken on the line 1212 ofFigure 2.

In the drawings, the numeral 10 designates a typical drilling bit whichincludes a body 11 having cutters 12.

The bit illustrated is generally referred to as a jet type bit whereinfluid streams under high velocity are directed downwardly and outwardlyagainst the formation being drilled. For directing these fluid jets ithas been the practice to form openings or nozzles in the bit bodyadjacent the cutters; these openings or nozzles are usually at an angleto the axial bore of the body and cause a rather abrupt change in theline of fluid flow with the result that the abrasive material in thecirculating fluid cuts out or damages the nozzles before the bit cuttersare fully worn. The present invention has to do with the provision of animproved nozzle construction applicable to the typical jet bit fordirecting the fluid streams in the desired direction.

The improved nozzle construction is clearly shown in Figures 1 to 3 andincludes a pair of duplicate sections or units A and B. Each sectionincludes an upper generally semi-cylindrical portion 13 which has itslower end merging into a tapered tubular nozzle portion 14 which isdisposed at an angle to said body portion, and said sections are adaptedto interflt with each other to form a complete nozzle assembly (Figure2). The nozzle assembly is arranged to be mounted within the bore 10a ofthe bit body which bore has itslower end flared at ltlb to accommodatethe inclined or flared nozzle portions. When the assembly is within thebit (Figure 1) the lower outlet end of each nozzle portion is disposedin proper position above the bit cutters 12 to properly direct or jetthe fluid in a desired manner.

As has been noted the upper portion 13 of each of the units A and B isgenerally semi-cylindrical in cross-section and the outer surface 13a iscurved while the inner surface 13b is substantially flat. At thejuncture of the flat inner surface 13b with the tubular nozzle portionthe surface of each unit is curved as indicated at 13c; the flat surface13b gradually merges into the surface 13c and the nozzle portion 14 isoifset or out of longitudinal alignment with the longitudinal axis ofthe upper portion 13, whereby the recess 13 is formed along one edge ofthe portion 13 adjacent the juncture between the portions 13 and 14.When the flat surfaces 13b of the sections A and B are placed inabutting contact relationship, the surfaces 13c which are complementaryto each other engage to result in perfect interfitting of the two unitsas shown in Figure 2. The complete assembly comprises the uppercylindrical portion having the flared or inclined nozzles extending fromits lower end in substantially diametrically opposed relationship.

The two units A and B of the nozzle assembly are welded together and theinner walls 13d of the connected units coact to form a central partitionor web extending longitudinally of said assembly to divide the assemblyinto two flow passages C and D. The transverse center line 13c (Figure10) of the web formed by the abutting walls of the units lies in avertical plane V which is substantially parallel to the planes V (Figure12) which may be termed the longitudinal axes of the nozzle portions 14of said unit; the lower end of the passage C communicates with the boreof one of the nozzles while the second passage D has communication withthe bore of the other nozzle. As is clearly shown in Figure 4, theparticular disposition of the dividing web with respect to the nozzlespermits the bore of each nozzle to become in effect a gradualcontinuation of its associated passage without any abrupt turn or offsetin the passage. The complete assembly comprising the connected units Aand B is then welded or otherwise suitably secured within the bit body,the weld being indicated at 15 in Figure 1.

It is noted that heretofore it has been the practice to dispose thedividing web in a longitudinal. plane which is at a right angle to theplane in which the longitudinal axis of each nozzle lies; in otherwords, referring to Figure 12, the web has been disposed in a planeindicated by the dotted line L and when so disposed the fluid was causedto make a relatively sharp turn from the upper end of the assembly intothe bore of the nozzle. By disposing the web in a longitudinal planewhich is substantially parallel to a plane through the longitudinal axisof the nozzle, a more gradual flow path without any abrupt curves ispossible and true streamlined flow through the assembly results.

Each passage or bore C and D which extends entirely through the portion13 of its respective unit and merges with the bore of its associatednozzle has the cross-sectional shape thereof varied from its upper toits lower end, as is clearly illustrated in Figures 5 to 9. At the upperend of each unit the bore 16 is substantially semicircular incross-section and as the bore reduces toward its lower end, the shape isgradually changed from semicircular in cross-section toward circular, asillustrated in Figure 7; as the passage merges into the bore of thenozzle it is of a shape as shown in Figure 8 and therebelow the bore ofthe nozzle gradually changes to truly circular, as shown in Figure 9.This gradual change of the shape of the passage through each unit ispermitted because of the disposition of the dividing web and providesfor a smooth streamlined flow through said passage; thus, after thedrilling fluid is divided into two streams by the central web, eachstream enters the relatively large upper end of each passage andthereafter there is no abrupt change in the direction of flow or asubsequent dividing of the flow, with the result that minimum abrasionof the interior surface of the passages and nozzle bores is had.

From the foregoing it will be evident that the passage or bore throughthe units provides a relatively streamlined path for the flowing fluid,whereby any abrasive wear will be spread over the large area of theentire passage or bore and will not cause undue wear at any particularpoint. The partition or web section formed by the abutting fiat innerwalls 13b of the two sections functions to divide the two nozzles flowstream into two flow paths which are conducted to the outlet end of thenozzle with a minimum amount of deflection of the fluid stream, wherebythe fluid streams are ejected from the nozzles at the desired positionsin relation to the bit. The construction of the nozzle assembly in twoseparate 4 units which are identical in construction facilitates castingof the units and also allows individual testing of each unit prior toassembly. Also, after the two sections are secured together the centralweb provides for a reinforcing rib extending throughout the entirelength of the assembly.

It may be desirable to mount a hardened insert in the outer end of eachnozzle and in Figure 12, such a construction is illustrated. In thisinstance, the outlet end of the bore of the nozzle is counterbored toreceive a collar or sleeve N which may be secured therein in anysuitable manner, and said collar or sleeve is constructed of hardenedmetal or other suitable wear-resisting material.

The foregoing disclosure and description of the invention isillustrative and explanatory thereof and various changes in the size,shape and materials, as well as in the details of the illustratedconstruction may be made, within the scope of the appended claims,without departing from the spirit of the invention.

Having described the invention, we claim:

1. A nozzle assembly for drill bits including a plurality of sectionsadapted to interfit and be secured together to form a unitary structure,each section comprising an upper tubular portion which is substantiallysemi-circular in cross-section whereby one wall of said portion issubstantially flat, said portion extending in axial alignment with thedrill bit in which the structure is mounted, and a lower nozzle portionwhich is disposed at an angle to the bit axis, each of said sectionsalso having a longitudinal passage extending entirely through both itsupper portion and its nozzle portion, the fiat wall of the upper portionlying in a longitudinal plane which is substantially parallel to alongitudinal plane through the axis of the nozzle portion andperpendicular to a plane from which said lower nozzle portion is offset.

2. A nozzle assembly as set forth in claim 1, wherein said lower nozzlesare offset from a plane perpendicular to the plane of the flat wall ofeach of said upper portions, and wherein said longitudinal passage islarger in crosssection at its upper end than at its lower end andwherein the variation in cross-sectional area is gradual from end to endof said passage, whereby no abrupt changes in direction of flow occurwithin said passage.

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